This invention relates to cardiac pacing leads, and more particularly to an improved method for anchoring a temporary pacing lead within the heart.
Temporary leads for use in connecting temporary cardiac pacers to the heart are well known in the medical profession. In general, such leads are constructed of a number of fine stainless steel wires twisted together to form a single, flexible, multiple strand, wire conductor. The major portion of the wire conductor is generally insulated with polyethylene, polytetrafluoroethylene, silicone rubber, nylon or other non-conductive coating. A short length of wire conductor at each end thereof is left uninsulated to provide a terminal forming portion. A curved surgical needle for piercing the heart tissue is mechanically and electrically attached by swaging the needle to one end of the wire conductor. The other end of the wire conductor is attached to a cutting type straight surgical needle for piercing the chest wall from the inside outward so that the wire conductor may be passed through the chest wall and connected to a cardiac pacer. When the temporary lead has been properly positioned, both of the needles are cut off of the ends of the wire conductor. The end of the wire conductor which is then outside of the body, the proximal end, is attached to the cardiac pacer for stimuling the heart. The other end of the wire conductor remains within the heart. A second lead is often used in a similar fashion to complete the circuit, or the return path may be through a stitch of wire in the skin. These prior art temporary leads have a common problem in that when the multiple strand, wire conductor has been passed through a wall of the heart and the needle has been removed, the wire conductor has a tendency to begin to fray or unravel. With the beating of the heart, strands of the wire conductor tend to move relative to the heart thereby preventing satisfactory conduction between the wire conductor and the heart. This causes irritation of the tissue and a rise in the amount of current required for stimulating the heart. In addition, the stranded wires tend to become dislodged from the wall of the heart thereby terminating any further stimulation of the heart.
The present invention contemplates a method of using a novel anchoring device to fix the position of the temporary pacing lead within the heart. In addition, the temporary pacing lead may be intentionally withdrawn from the wall of the heart at a subsequent date from a position external to the body without damage to the heart.